Double Fertilisation — Unsolved Practice Set
Chapter: Sexual Reproduction in Flowering Plants | Topic: Double Fertilisation
DOUBLE FERTILISATION — UNSOLVED PRACTICE SET
Topic: Double Fertilisation
Multiple Choice Questions
Q1. The term "double fertilisation" was first described by:
- Robert Brown
- Nawaschin
- Strasburger
- Darwin
Q2. Triple fusion involves the fusion of:
- Egg + one male gamete
- Two polar nuclei + one male gamete
- Synergid + male gamete
- Egg + two male gametes
Q3. The direct product of syngamy is a:
- Diploid zygote
- Triploid PEN
- Haploid spore
- Tetraploid cell
Q4. The primary endosperm nucleus (PEN) formed after triple fusion is usually:
- Haploid
- Diploid
- Triploid
- Tetraploid
Q5. Double fertilisation is a unique feature found exclusively in:
- Gymnosperms
- Angiosperms
- Bryophytes
- Pteridophytes
Short Answer Questions
Q6. Define double fertilisation and name the two fusion events involved in it.
Q7. Why is double fertilisation considered a unique event, found only in flowering plants?
Q8. State the ploidy of the zygote and of the primary endosperm nucleus formed after double fertilisation.
Q9. Which two male gametes are involved in double fertilisation, and where do they originally come from?
Long Answer Questions
Q10. Describe the two fusion events that together constitute double fertilisation, mentioning the cells involved and the products formed in each case.
Q11. Explain the biological significance of triple fusion in the development of the seed, linking it to the nutritive role of the endosperm.
APPLICATION / ANALYSIS
Q12. If, hypothetically, only syngamy occurred in a flower and triple fusion failed to take place, predict what would happen to the developing seed. Explain your reasoning based on the role of the endosperm.
Q13. A geneticist studying the ploidy of tissues in a developing seed finds three distinct ploidy levels within the same seed. Identify these three tissues along with their respective ploidy levels, and explain how double fertilisation accounts for this diversity.